<?php

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2010 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
// $Id$

/**
  +------------------------------------------------------------------------------
 * 静态缓存类
 * 支持静态缓存规则定义
  +------------------------------------------------------------------------------
 * @category   Think
 * @package  Think
 * @subpackage  Util
 * @author liu21st <liu21st@gmail.com>
 * @version  $Id$
  +------------------------------------------------------------------------------
 */
class HtmlCache extends Think {

    static private $cacheTime = null; // 缓存有效期（支持函数）
    static private $requireCache = false;    // 是否需要缓存

    // 判断是否需要静态缓存

    static private function requireHtmlCache() {
	// 分析当前的静态规则
	$htmls = C('_htmls_'); // 读取静态规则
	if (!empty($htmls)) {
	    // 静态规则文件定义格式 actionName=>array(‘静态规则’,’缓存时间’,’附加规则')
	    // 'read'=>array('{id},{name}',60,'md5') 必须保证静态规则的唯一性 和 可判断性
	    // 检测静态规则
	    $groupName = strtolower(GROUP_NAME); // yunzhi.li.08@gmail.com
	    $moduleName = strtolower(MODULE_NAME);
	    if (isset($htmls[$groupName . '-' . $moduleName . ':' . ACTION_NAME])) { // yunzhi.li.08@gmail.com
		$html = $htmls[$groupName . '-' . $moduleName . ':' . ACTION_NAME];   // 某个分组中模块的操作静态规则
	    } elseif (isset($htmls[$groupName . '-' . $moduleName . ':'])) { // yunzhi.li.08@gmail.com
		$html = $htmls[$groupName . '-' . $moduleName . ':'];   // 某个分组中模块的静态规则
	    } elseif (isset($htmls[$groupName . '-'])) { // yunzhi.li.08@gmail.com
		$html = $htmls[$groupName . '-'];   // 某个分组的静态规则
	    } elseif (isset($htmls[$moduleName . ':' . ACTION_NAME])) {
		$html = $htmls[$moduleName . ':' . ACTION_NAME];   // 某个模块的操作的静态规则
	    } elseif (isset($htmls[$moduleName . ':'])) {// 某个模块的静态规则
		$html = $htmls[$moduleName . ':'];
	    } elseif (isset($htmls[ACTION_NAME])) {
		$html = $htmls[ACTION_NAME]; // 所有操作的静态规则
	    } elseif (isset($htmls['*'])) {
		$html = $htmls['*']; // 全局静态规则
	    } elseif (isset($htmls['empty:index']) && !class_exists(MODULE_NAME . 'Action')) {
		$html = $htmls['empty:index']; // 空模块静态规则
	    } elseif (isset($htmls[$moduleName . ':_empty']) && self::isEmptyAction(MODULE_NAME, ACTION_NAME)) {
		$html = $htmls[$moduleName . ':_empty']; // 空操作静态规则
	    }

	    if (!empty($html)) {
		self::$requireCache = true; // 需要缓存
		// 解读静态规则
		$rule = $html[0];
		// 以$_开头的系统变量
		$rule = preg_replace('/{\$(_\w+)\.(\w+)\|(\w+)}/e', "\\3(\$\\1['\\2'])", $rule);
		$rule = preg_replace('/{\$(_\w+)\.(\w+)}/e', "\$\\1['\\2']", $rule);
		// {ID|FUN} GET变量的简写
		$rule = preg_replace('/{(\w+)\|(\w+)}/e', "\\2(\$_GET['\\1'])", $rule);
		$rule = preg_replace('/{(\w+)}/e', "\$_GET['\\1']", $rule);
		// 特殊系统变量
		$rule = str_ireplace(
			array('{:app}', '{:module}', '{:action}', '{:group}'), array(APP_NAME, MODULE_NAME, ACTION_NAME, defined('GROUP_NAME') ? GROUP_NAME : ''), $rule);
		// {|FUN} 单独使用函数
		$rule = preg_replace('/{|(\w+)}/e', "\\1()", $rule);
		if (!empty($html[2]))
		    $rule = $html[2]($rule); // 应用附加函数
		self::$cacheTime = isset($html[1]) ? $html[1] : C('HTML_CACHE_TIME'); // 缓存有效期
		// 当前缓存文件
		define('HTML_FILE_NAME', HTML_PATH . $rule . C('HTML_FILE_SUFFIX'));
		return true;
	    }
	}
	// 无需缓存
	return false;
    }

    /**
      +----------------------------------------------------------
     * 读取静态缓存
      +----------------------------------------------------------
     * @access static
      +----------------------------------------------------------
     * @return void
      +----------------------------------------------------------
     */
    static function readHTMLCache() {
	if (self::requireHtmlCache() && self::checkHTMLCache(HTML_FILE_NAME, self::$cacheTime)) { //静态页面有效
	    if (C('HTML_READ_TYPE') == 1) {
		// 重定向到静态页面
		redirect(str_replace(array(realpath($_SERVER["DOCUMENT_ROOT"]), "\\"), array('', "/"), realpath(HTML_FILE_NAME)));
	    } else {
		// 读取静态页面输出
		readfile(HTML_FILE_NAME);
		exit();
	    }
	}
	return;
    }

    /**
      +----------------------------------------------------------
     * 写入静态缓存
      +----------------------------------------------------------
     * @access public
      +----------------------------------------------------------
     * @param string $content 页面内容
      +----------------------------------------------------------
     * @return void
      +----------------------------------------------------------
     * @throws ThinkExecption
      +----------------------------------------------------------
     */
    static public function writeHTMLCache($content) {
	if (self::$requireCache) {
	    //静态文件写入
	    // 如果开启HTML功能 检查并重写HTML文件
	    // 没有模版的操作不生成静态文件
	    if (!is_dir(dirname(HTML_FILE_NAME)))
		mk_dir(dirname(HTML_FILE_NAME));
	    if (false === file_put_contents(HTML_FILE_NAME, $content))
		throw_exception(L('_CACHE_WRITE_ERROR_') . ':' . HTML_FILE_NAME);
	}
	return;
    }

    /**
      +----------------------------------------------------------
     * 检查静态HTML文件是否有效
     * 如果无效需要重新更新
      +----------------------------------------------------------
     * @access public
      +----------------------------------------------------------
     * @param string $cacheFile  静态文件名
     * @param integer $cacheTime  缓存有效期
      +----------------------------------------------------------
     * @return boolen
      +----------------------------------------------------------
     */
    static public function checkHTMLCache($cacheFile='', $cacheTime='') {
	if (!is_file($cacheFile)) {
	    return false;
	} elseif (filemtime(C('TMPL_FILE_NAME')) > filemtime($cacheFile)) {
	    // 模板文件如果更新静态文件需要更新
	    return false;
	} elseif (!is_numeric($cacheTime) && function_exists($cacheTime)) {
	    return $cacheTime($cacheFile);
	} elseif ($cacheTime != -1 && time() > filemtime($cacheFile) + $cacheTime) {
	    // 文件是否在有效期
	    return false;
	}
	//静态文件有效
	return true;
    }

    //检测是否是空操作
    static private function isEmptyAction($module, $action) {
	$className = $module . 'Action';
	$class = new $className;
	return!method_exists($class, $action);
    }

}

?>